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-rw-r--r--drivers/mmc/core/host.c678
1 files changed, 678 insertions, 0 deletions
diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
new file mode 100644
index 000000000..25c152ef5
--- /dev/null
+++ b/drivers/mmc/core/host.c
@@ -0,0 +1,678 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * linux/drivers/mmc/core/host.c
+ *
+ * Copyright (C) 2003 Russell King, All Rights Reserved.
+ * Copyright (C) 2007-2008 Pierre Ossman
+ * Copyright (C) 2010 Linus Walleij
+ *
+ * MMC host class device management
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/idr.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/pagemap.h>
+#include <linux/pm_wakeup.h>
+#include <linux/export.h>
+#include <linux/leds.h>
+#include <linux/slab.h>
+
+#include <linux/mmc/host.h>
+#include <linux/mmc/card.h>
+#include <linux/mmc/slot-gpio.h>
+
+#include "core.h"
+#include "crypto.h"
+#include "host.h"
+#include "slot-gpio.h"
+#include "pwrseq.h"
+#include "sdio_ops.h"
+
+#define cls_dev_to_mmc_host(d) container_of(d, struct mmc_host, class_dev)
+
+static DEFINE_IDA(mmc_host_ida);
+
+#ifdef CONFIG_PM_SLEEP
+static int mmc_host_class_prepare(struct device *dev)
+{
+ struct mmc_host *host = cls_dev_to_mmc_host(dev);
+
+ /*
+ * It's safe to access the bus_ops pointer, as both userspace and the
+ * workqueue for detecting cards are frozen at this point.
+ */
+ if (!host->bus_ops)
+ return 0;
+
+ /* Validate conditions for system suspend. */
+ if (host->bus_ops->pre_suspend)
+ return host->bus_ops->pre_suspend(host);
+
+ return 0;
+}
+
+static void mmc_host_class_complete(struct device *dev)
+{
+ struct mmc_host *host = cls_dev_to_mmc_host(dev);
+
+ _mmc_detect_change(host, 0, false);
+}
+
+static const struct dev_pm_ops mmc_host_class_dev_pm_ops = {
+ .prepare = mmc_host_class_prepare,
+ .complete = mmc_host_class_complete,
+};
+
+#define MMC_HOST_CLASS_DEV_PM_OPS (&mmc_host_class_dev_pm_ops)
+#else
+#define MMC_HOST_CLASS_DEV_PM_OPS NULL
+#endif
+
+static void mmc_host_classdev_release(struct device *dev)
+{
+ struct mmc_host *host = cls_dev_to_mmc_host(dev);
+ wakeup_source_unregister(host->ws);
+ if (of_alias_get_id(host->parent->of_node, "mmc") < 0)
+ ida_simple_remove(&mmc_host_ida, host->index);
+ kfree(host);
+}
+
+static int mmc_host_classdev_shutdown(struct device *dev)
+{
+ struct mmc_host *host = cls_dev_to_mmc_host(dev);
+
+ __mmc_stop_host(host);
+ return 0;
+}
+
+static struct class mmc_host_class = {
+ .name = "mmc_host",
+ .dev_release = mmc_host_classdev_release,
+ .shutdown_pre = mmc_host_classdev_shutdown,
+ .pm = MMC_HOST_CLASS_DEV_PM_OPS,
+};
+
+int mmc_register_host_class(void)
+{
+ return class_register(&mmc_host_class);
+}
+
+void mmc_unregister_host_class(void)
+{
+ class_unregister(&mmc_host_class);
+}
+
+/**
+ * mmc_retune_enable() - enter a transfer mode that requires retuning
+ * @host: host which should retune now
+ */
+void mmc_retune_enable(struct mmc_host *host)
+{
+ host->can_retune = 1;
+ if (host->retune_period)
+ mod_timer(&host->retune_timer,
+ jiffies + host->retune_period * HZ);
+}
+
+/*
+ * Pause re-tuning for a small set of operations. The pause begins after the
+ * next command and after first doing re-tuning.
+ */
+void mmc_retune_pause(struct mmc_host *host)
+{
+ if (!host->retune_paused) {
+ host->retune_paused = 1;
+ mmc_retune_needed(host);
+ mmc_retune_hold(host);
+ }
+}
+EXPORT_SYMBOL(mmc_retune_pause);
+
+void mmc_retune_unpause(struct mmc_host *host)
+{
+ if (host->retune_paused) {
+ host->retune_paused = 0;
+ mmc_retune_release(host);
+ }
+}
+EXPORT_SYMBOL(mmc_retune_unpause);
+
+/**
+ * mmc_retune_disable() - exit a transfer mode that requires retuning
+ * @host: host which should not retune anymore
+ *
+ * It is not meant for temporarily preventing retuning!
+ */
+void mmc_retune_disable(struct mmc_host *host)
+{
+ mmc_retune_unpause(host);
+ host->can_retune = 0;
+ del_timer_sync(&host->retune_timer);
+ mmc_retune_clear(host);
+}
+
+void mmc_retune_timer_stop(struct mmc_host *host)
+{
+ del_timer_sync(&host->retune_timer);
+}
+EXPORT_SYMBOL(mmc_retune_timer_stop);
+
+void mmc_retune_hold(struct mmc_host *host)
+{
+ if (!host->hold_retune)
+ host->retune_now = 1;
+ host->hold_retune += 1;
+}
+
+void mmc_retune_release(struct mmc_host *host)
+{
+ if (host->hold_retune)
+ host->hold_retune -= 1;
+ else
+ WARN_ON(1);
+}
+EXPORT_SYMBOL(mmc_retune_release);
+
+int mmc_retune(struct mmc_host *host)
+{
+ bool return_to_hs400 = false;
+ int err;
+
+ if (host->retune_now)
+ host->retune_now = 0;
+ else
+ return 0;
+
+ if (!host->need_retune || host->doing_retune || !host->card)
+ return 0;
+
+ host->need_retune = 0;
+
+ host->doing_retune = 1;
+
+ if (host->ios.timing == MMC_TIMING_MMC_HS400) {
+ err = mmc_hs400_to_hs200(host->card);
+ if (err)
+ goto out;
+
+ return_to_hs400 = true;
+ }
+
+ err = mmc_execute_tuning(host->card);
+ if (err)
+ goto out;
+
+ if (return_to_hs400)
+ err = mmc_hs200_to_hs400(host->card);
+out:
+ host->doing_retune = 0;
+
+ return err;
+}
+
+static void mmc_retune_timer(struct timer_list *t)
+{
+ struct mmc_host *host = from_timer(host, t, retune_timer);
+
+ mmc_retune_needed(host);
+}
+
+static void mmc_of_parse_timing_phase(struct device *dev, const char *prop,
+ struct mmc_clk_phase *phase)
+{
+ int degrees[2] = {0};
+ int rc;
+
+ rc = device_property_read_u32_array(dev, prop, degrees, 2);
+ phase->valid = !rc;
+ if (phase->valid) {
+ phase->in_deg = degrees[0];
+ phase->out_deg = degrees[1];
+ }
+}
+
+void
+mmc_of_parse_clk_phase(struct mmc_host *host, struct mmc_clk_phase_map *map)
+{
+ struct device *dev = host->parent;
+
+ mmc_of_parse_timing_phase(dev, "clk-phase-legacy",
+ &map->phase[MMC_TIMING_LEGACY]);
+ mmc_of_parse_timing_phase(dev, "clk-phase-mmc-hs",
+ &map->phase[MMC_TIMING_MMC_HS]);
+ mmc_of_parse_timing_phase(dev, "clk-phase-sd-hs",
+ &map->phase[MMC_TIMING_SD_HS]);
+ mmc_of_parse_timing_phase(dev, "clk-phase-uhs-sdr12",
+ &map->phase[MMC_TIMING_UHS_SDR12]);
+ mmc_of_parse_timing_phase(dev, "clk-phase-uhs-sdr25",
+ &map->phase[MMC_TIMING_UHS_SDR25]);
+ mmc_of_parse_timing_phase(dev, "clk-phase-uhs-sdr50",
+ &map->phase[MMC_TIMING_UHS_SDR50]);
+ mmc_of_parse_timing_phase(dev, "clk-phase-uhs-sdr104",
+ &map->phase[MMC_TIMING_UHS_SDR104]);
+ mmc_of_parse_timing_phase(dev, "clk-phase-uhs-ddr50",
+ &map->phase[MMC_TIMING_UHS_DDR50]);
+ mmc_of_parse_timing_phase(dev, "clk-phase-mmc-ddr52",
+ &map->phase[MMC_TIMING_MMC_DDR52]);
+ mmc_of_parse_timing_phase(dev, "clk-phase-mmc-hs200",
+ &map->phase[MMC_TIMING_MMC_HS200]);
+ mmc_of_parse_timing_phase(dev, "clk-phase-mmc-hs400",
+ &map->phase[MMC_TIMING_MMC_HS400]);
+}
+EXPORT_SYMBOL(mmc_of_parse_clk_phase);
+
+/**
+ * mmc_of_parse() - parse host's device properties
+ * @host: host whose properties should be parsed.
+ *
+ * To keep the rest of the MMC subsystem unaware of whether DT has been
+ * used to to instantiate and configure this host instance or not, we
+ * parse the properties and set respective generic mmc-host flags and
+ * parameters.
+ */
+int mmc_of_parse(struct mmc_host *host)
+{
+ struct device *dev = host->parent;
+ u32 bus_width, drv_type, cd_debounce_delay_ms;
+ int ret;
+
+ if (!dev || !dev_fwnode(dev))
+ return 0;
+
+ /* "bus-width" is translated to MMC_CAP_*_BIT_DATA flags */
+ if (device_property_read_u32(dev, "bus-width", &bus_width) < 0) {
+ dev_dbg(host->parent,
+ "\"bus-width\" property is missing, assuming 1 bit.\n");
+ bus_width = 1;
+ }
+
+ switch (bus_width) {
+ case 8:
+ host->caps |= MMC_CAP_8_BIT_DATA;
+ fallthrough; /* Hosts capable of 8-bit can also do 4 bits */
+ case 4:
+ host->caps |= MMC_CAP_4_BIT_DATA;
+ break;
+ case 1:
+ break;
+ default:
+ dev_err(host->parent,
+ "Invalid \"bus-width\" value %u!\n", bus_width);
+ return -EINVAL;
+ }
+
+ /* f_max is obtained from the optional "max-frequency" property */
+ device_property_read_u32(dev, "max-frequency", &host->f_max);
+
+ /*
+ * Configure CD and WP pins. They are both by default active low to
+ * match the SDHCI spec. If GPIOs are provided for CD and / or WP, the
+ * mmc-gpio helpers are used to attach, configure and use them. If
+ * polarity inversion is specified in DT, one of MMC_CAP2_CD_ACTIVE_HIGH
+ * and MMC_CAP2_RO_ACTIVE_HIGH capability-2 flags is set. If the
+ * "broken-cd" property is provided, the MMC_CAP_NEEDS_POLL capability
+ * is set. If the "non-removable" property is found, the
+ * MMC_CAP_NONREMOVABLE capability is set and no card-detection
+ * configuration is performed.
+ */
+
+ /* Parse Card Detection */
+
+ if (device_property_read_bool(dev, "non-removable")) {
+ host->caps |= MMC_CAP_NONREMOVABLE;
+ } else {
+ if (device_property_read_bool(dev, "cd-inverted"))
+ host->caps2 |= MMC_CAP2_CD_ACTIVE_HIGH;
+
+ if (device_property_read_u32(dev, "cd-debounce-delay-ms",
+ &cd_debounce_delay_ms))
+ cd_debounce_delay_ms = 200;
+
+ if (device_property_read_bool(dev, "broken-cd"))
+ host->caps |= MMC_CAP_NEEDS_POLL;
+
+ ret = mmc_gpiod_request_cd(host, "cd", 0, false,
+ cd_debounce_delay_ms * 1000);
+ if (!ret)
+ dev_info(host->parent, "Got CD GPIO\n");
+ else if (ret != -ENOENT && ret != -ENOSYS)
+ return ret;
+ }
+
+ /* Parse Write Protection */
+
+ if (device_property_read_bool(dev, "wp-inverted"))
+ host->caps2 |= MMC_CAP2_RO_ACTIVE_HIGH;
+
+ ret = mmc_gpiod_request_ro(host, "wp", 0, 0);
+ if (!ret)
+ dev_info(host->parent, "Got WP GPIO\n");
+ else if (ret != -ENOENT && ret != -ENOSYS)
+ return ret;
+
+ if (device_property_read_bool(dev, "disable-wp"))
+ host->caps2 |= MMC_CAP2_NO_WRITE_PROTECT;
+
+ if (device_property_read_bool(dev, "cap-sd-highspeed"))
+ host->caps |= MMC_CAP_SD_HIGHSPEED;
+ if (device_property_read_bool(dev, "cap-mmc-highspeed"))
+ host->caps |= MMC_CAP_MMC_HIGHSPEED;
+ if (device_property_read_bool(dev, "sd-uhs-sdr12"))
+ host->caps |= MMC_CAP_UHS_SDR12;
+ if (device_property_read_bool(dev, "sd-uhs-sdr25"))
+ host->caps |= MMC_CAP_UHS_SDR25;
+ if (device_property_read_bool(dev, "sd-uhs-sdr50"))
+ host->caps |= MMC_CAP_UHS_SDR50;
+ if (device_property_read_bool(dev, "sd-uhs-sdr104"))
+ host->caps |= MMC_CAP_UHS_SDR104;
+ if (device_property_read_bool(dev, "sd-uhs-ddr50"))
+ host->caps |= MMC_CAP_UHS_DDR50;
+ if (device_property_read_bool(dev, "cap-power-off-card"))
+ host->caps |= MMC_CAP_POWER_OFF_CARD;
+ if (device_property_read_bool(dev, "cap-mmc-hw-reset"))
+ host->caps |= MMC_CAP_HW_RESET;
+ if (device_property_read_bool(dev, "cap-sdio-irq"))
+ host->caps |= MMC_CAP_SDIO_IRQ;
+ if (device_property_read_bool(dev, "full-pwr-cycle"))
+ host->caps2 |= MMC_CAP2_FULL_PWR_CYCLE;
+ if (device_property_read_bool(dev, "full-pwr-cycle-in-suspend"))
+ host->caps2 |= MMC_CAP2_FULL_PWR_CYCLE_IN_SUSPEND;
+ if (device_property_read_bool(dev, "keep-power-in-suspend"))
+ host->pm_caps |= MMC_PM_KEEP_POWER;
+ if (device_property_read_bool(dev, "wakeup-source") ||
+ device_property_read_bool(dev, "enable-sdio-wakeup")) /* legacy */
+ host->pm_caps |= MMC_PM_WAKE_SDIO_IRQ;
+ if (device_property_read_bool(dev, "mmc-ddr-3_3v"))
+ host->caps |= MMC_CAP_3_3V_DDR;
+ if (device_property_read_bool(dev, "mmc-ddr-1_8v"))
+ host->caps |= MMC_CAP_1_8V_DDR;
+ if (device_property_read_bool(dev, "mmc-ddr-1_2v"))
+ host->caps |= MMC_CAP_1_2V_DDR;
+ if (device_property_read_bool(dev, "mmc-hs200-1_8v"))
+ host->caps2 |= MMC_CAP2_HS200_1_8V_SDR;
+ if (device_property_read_bool(dev, "mmc-hs200-1_2v"))
+ host->caps2 |= MMC_CAP2_HS200_1_2V_SDR;
+ if (device_property_read_bool(dev, "mmc-hs400-1_8v"))
+ host->caps2 |= MMC_CAP2_HS400_1_8V | MMC_CAP2_HS200_1_8V_SDR;
+ if (device_property_read_bool(dev, "mmc-hs400-1_2v"))
+ host->caps2 |= MMC_CAP2_HS400_1_2V | MMC_CAP2_HS200_1_2V_SDR;
+ if (device_property_read_bool(dev, "mmc-hs400-enhanced-strobe"))
+ host->caps2 |= MMC_CAP2_HS400_ES;
+ if (device_property_read_bool(dev, "no-sdio"))
+ host->caps2 |= MMC_CAP2_NO_SDIO;
+ if (device_property_read_bool(dev, "no-sd"))
+ host->caps2 |= MMC_CAP2_NO_SD;
+ if (device_property_read_bool(dev, "no-mmc"))
+ host->caps2 |= MMC_CAP2_NO_MMC;
+ if (device_property_read_bool(dev, "no-mmc-hs400"))
+ host->caps2 &= ~(MMC_CAP2_HS400_1_8V | MMC_CAP2_HS400_1_2V |
+ MMC_CAP2_HS400_ES);
+
+ /* Must be after "non-removable" check */
+ if (device_property_read_u32(dev, "fixed-emmc-driver-type", &drv_type) == 0) {
+ if (host->caps & MMC_CAP_NONREMOVABLE)
+ host->fixed_drv_type = drv_type;
+ else
+ dev_err(host->parent,
+ "can't use fixed driver type, media is removable\n");
+ }
+
+ host->dsr_req = !device_property_read_u32(dev, "dsr", &host->dsr);
+ if (host->dsr_req && (host->dsr & ~0xffff)) {
+ dev_err(host->parent,
+ "device tree specified broken value for DSR: 0x%x, ignoring\n",
+ host->dsr);
+ host->dsr_req = 0;
+ }
+
+ device_property_read_u32(dev, "post-power-on-delay-ms",
+ &host->ios.power_delay_ms);
+
+ return mmc_pwrseq_alloc(host);
+}
+
+EXPORT_SYMBOL(mmc_of_parse);
+
+/**
+ * mmc_of_parse_voltage - return mask of supported voltages
+ * @host: host whose properties should be parsed.
+ * @mask: mask of voltages available for MMC/SD/SDIO
+ *
+ * Parse the "voltage-ranges" property, returning zero if it is not
+ * found, negative errno if the voltage-range specification is invalid,
+ * or one if the voltage-range is specified and successfully parsed.
+ */
+int mmc_of_parse_voltage(struct mmc_host *host, u32 *mask)
+{
+ const char *prop = "voltage-ranges";
+ struct device *dev = host->parent;
+ u32 *voltage_ranges;
+ int num_ranges, i;
+ int ret;
+
+ if (!device_property_present(dev, prop)) {
+ dev_dbg(dev, "%s unspecified\n", prop);
+ return 0;
+ }
+
+ ret = device_property_count_u32(dev, prop);
+ if (ret < 0)
+ return ret;
+
+ num_ranges = ret / 2;
+ if (!num_ranges) {
+ dev_err(dev, "%s empty\n", prop);
+ return -EINVAL;
+ }
+
+ voltage_ranges = kcalloc(2 * num_ranges, sizeof(*voltage_ranges), GFP_KERNEL);
+ if (!voltage_ranges)
+ return -ENOMEM;
+
+ ret = device_property_read_u32_array(dev, prop, voltage_ranges, 2 * num_ranges);
+ if (ret) {
+ kfree(voltage_ranges);
+ return ret;
+ }
+
+ for (i = 0; i < num_ranges; i++) {
+ const int j = i * 2;
+ u32 ocr_mask;
+
+ ocr_mask = mmc_vddrange_to_ocrmask(voltage_ranges[j + 0],
+ voltage_ranges[j + 1]);
+ if (!ocr_mask) {
+ dev_err(dev, "range #%d in %s is invalid\n", i, prop);
+ kfree(voltage_ranges);
+ return -EINVAL;
+ }
+ *mask |= ocr_mask;
+ }
+
+ kfree(voltage_ranges);
+
+ return 1;
+}
+EXPORT_SYMBOL(mmc_of_parse_voltage);
+
+/**
+ * mmc_first_nonreserved_index() - get the first index that is not reserved
+ */
+static int mmc_first_nonreserved_index(void)
+{
+ int max;
+
+ max = of_alias_get_highest_id("mmc");
+ if (max < 0)
+ return 0;
+
+ return max + 1;
+}
+
+/**
+ * mmc_alloc_host - initialise the per-host structure.
+ * @extra: sizeof private data structure
+ * @dev: pointer to host device model structure
+ *
+ * Initialise the per-host structure.
+ */
+struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
+{
+ int index;
+ struct mmc_host *host;
+ int alias_id, min_idx, max_idx;
+
+ host = kzalloc(sizeof(struct mmc_host) + extra, GFP_KERNEL);
+ if (!host)
+ return NULL;
+
+ /* scanning will be enabled when we're ready */
+ host->rescan_disable = 1;
+
+ alias_id = of_alias_get_id(dev->of_node, "mmc");
+ if (alias_id >= 0) {
+ index = alias_id;
+ } else {
+ min_idx = mmc_first_nonreserved_index();
+ max_idx = 0;
+
+ index = ida_simple_get(&mmc_host_ida, min_idx, max_idx, GFP_KERNEL);
+ if (index < 0) {
+ kfree(host);
+ return NULL;
+ }
+ }
+
+ host->index = index;
+
+ dev_set_name(&host->class_dev, "mmc%d", host->index);
+ host->ws = wakeup_source_register(NULL, dev_name(&host->class_dev));
+
+ host->parent = dev;
+ host->class_dev.parent = dev;
+ host->class_dev.class = &mmc_host_class;
+ device_initialize(&host->class_dev);
+ device_enable_async_suspend(&host->class_dev);
+
+ if (mmc_gpio_alloc(host)) {
+ put_device(&host->class_dev);
+ return NULL;
+ }
+
+ spin_lock_init(&host->lock);
+ init_waitqueue_head(&host->wq);
+ INIT_DELAYED_WORK(&host->detect, mmc_rescan);
+ INIT_WORK(&host->sdio_irq_work, sdio_irq_work);
+ timer_setup(&host->retune_timer, mmc_retune_timer, 0);
+
+ /*
+ * By default, hosts do not support SGIO or large requests.
+ * They have to set these according to their abilities.
+ */
+ host->max_segs = 1;
+ host->max_seg_size = PAGE_SIZE;
+
+ host->max_req_size = PAGE_SIZE;
+ host->max_blk_size = 512;
+ host->max_blk_count = PAGE_SIZE / 512;
+
+ host->fixed_drv_type = -EINVAL;
+ host->ios.power_delay_ms = 10;
+ host->ios.power_mode = MMC_POWER_UNDEFINED;
+
+ return host;
+}
+
+EXPORT_SYMBOL(mmc_alloc_host);
+
+static int mmc_validate_host_caps(struct mmc_host *host)
+{
+ struct device *dev = host->parent;
+ u32 caps = host->caps, caps2 = host->caps2;
+
+ if (caps & MMC_CAP_SDIO_IRQ && !host->ops->enable_sdio_irq) {
+ dev_warn(dev, "missing ->enable_sdio_irq() ops\n");
+ return -EINVAL;
+ }
+
+ if (caps2 & (MMC_CAP2_HS400_ES | MMC_CAP2_HS400) &&
+ !(caps & MMC_CAP_8_BIT_DATA) && !(caps2 & MMC_CAP2_NO_MMC)) {
+ dev_warn(dev, "drop HS400 support since no 8-bit bus\n");
+ host->caps2 = caps2 & ~MMC_CAP2_HS400_ES & ~MMC_CAP2_HS400;
+ }
+
+ return 0;
+}
+
+/**
+ * mmc_add_host - initialise host hardware
+ * @host: mmc host
+ *
+ * Register the host with the driver model. The host must be
+ * prepared to start servicing requests before this function
+ * completes.
+ */
+int mmc_add_host(struct mmc_host *host)
+{
+ int err;
+
+ err = mmc_validate_host_caps(host);
+ if (err)
+ return err;
+
+ err = device_add(&host->class_dev);
+ if (err)
+ return err;
+
+ led_trigger_register_simple(dev_name(&host->class_dev), &host->led);
+
+#ifdef CONFIG_DEBUG_FS
+ mmc_add_host_debugfs(host);
+#endif
+
+ mmc_start_host(host);
+ return 0;
+}
+
+EXPORT_SYMBOL(mmc_add_host);
+
+/**
+ * mmc_remove_host - remove host hardware
+ * @host: mmc host
+ *
+ * Unregister and remove all cards associated with this host,
+ * and power down the MMC bus. No new requests will be issued
+ * after this function has returned.
+ */
+void mmc_remove_host(struct mmc_host *host)
+{
+ mmc_stop_host(host);
+
+#ifdef CONFIG_DEBUG_FS
+ mmc_remove_host_debugfs(host);
+#endif
+
+ device_del(&host->class_dev);
+
+ led_trigger_unregister_simple(host->led);
+}
+
+EXPORT_SYMBOL(mmc_remove_host);
+
+/**
+ * mmc_free_host - free the host structure
+ * @host: mmc host
+ *
+ * Free the host once all references to it have been dropped.
+ */
+void mmc_free_host(struct mmc_host *host)
+{
+ cancel_delayed_work_sync(&host->detect);
+ mmc_pwrseq_free(host);
+ put_device(&host->class_dev);
+}
+
+EXPORT_SYMBOL(mmc_free_host);